# Tag Archives: links

## Pi-ling Up On Pi

Friends, Romans, countrymen, lend me your ears …

Oops, sorry, you can have your ears back (hope they still fit on the sides of your head); the ides of March are not ’til tomorrow.

But still, friends of pi, do pay heed! For there is foul news afoot this year on pi day (today, 3/14). The naysayers are clamoring against the number pi and its day.

A new majority in Congress thinks such celebrations are frivolous:

“Last Congress, Democrats voted hand over fist to increase spending, in addition to overusing the suspension calendar for hundreds of needless votes on resolutions honoring items such as Confucius’ birthday and ‘PI’ day,” wrote Brad Dayspring, a spokesman for House Majority Leader Eric Cantor (R-Va.)

Bloggers question the narrowness of confining ourselves to the decimal system and to the middle-endian calendar. [Yes, I’m aware the second blogger is me; I enjoy arguing against myself.]

And the new hero of the math vlogosphere, with her wonderful series about doodling in math class, Vi Hart, has even taken a stand against Pi and Pi Day. Instead she advocates for Tau Day (a.k.a 2pi day, on 6/28) since tau is “more natural” than pi. Click on that latter link and watch her anti-pi video, as it is our most formidable opponent, taking on not just the representation of pi or its holiday-worthiness, but the essence of the number itself.

However, partisans of pi, we shall hold strong! Strong as the trees in the forest!

Photo (c) Kenneth Vincent

Now I ask of you, when a person comes across a circle in the woods, what can one measure about that circle? The circumference, of course, by tying a string or tape measure around the outside of the circle. And the diameter, using a tool like a dial caliper (we use these in the engineering classes I teach!). But one cannot measure the radius without tearing apart the circle and violating its circleness by poking at its innards. Besides, even with the careless circumvention of morals that cutting up a circle would entail, how would one determine that circle’s center to then find the radius? One would simply take a diameter and cut it in twain!–there lies our center.

Thus, pi = C/d is much more natural indeed, based on real-world experience, than tau = C/r. Not the reverse, as Ms. Hart claims!

And so, I issue a call to pi devotees everywhere to use this day to trumpet the glories of pi, as we face its enemies near and far! May your circles always be round!

______________________________

NOTE: It has come to my attention that I may be indulging in a bit of hypocrisy with my tirade toward tau. I guess my real opinion is: the more days celebrating pi, its cousins, and all of mathematics, the better. Avery’s conclusion that all of March should be pi month, or Vi’s appeal to celebrate tau day in June, all sound good to me!

In that vein of mathematical mellow-ness, here are a few more pi links that you might enjoy:

• A National Geographic blog post by someone at the Exploratorium (a San Francisco museum that invented or at least popularized pi day).
• A musical composition based on pi. High school friend Brett and I scooped them on this by nine years, using the computers in the band room to compose a pi-digit tune (that wasn’t all that tuneful). The linked video is a very nice rendition of our song, though! 😉
• A pi puzzle (I’ve enjoyed their puzzles each year past, and look forward to working on this one).

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## Iced In

Yesterday school was closed in Baltimore City and the surrounding counties due to active sleet + freezing rain, and icy conditions. What with Martin Luther King Day on Monday, a professional development held at Morgan State University for me today, and the possibility of another storm coming Thursday night into Friday morning, this could end up being a 1 day week for me! Not, of course in terms of me only working one day: I worked significant amounts on Tuesday while iced in, today was a full day that began with a 6:15 trip to the office (i.e. school), and Friday will include time spent grading and preparing for the new semester courses no matter what else it entails. But Thursday might be the only day this week I interact with students [in person].

Often when there are snow days, I try to communicate with students by e-mail, about something they can be doing to keep up the work in my class. Certainly not every student has access to the internet or checks his/her e-mail on a snow day, so the e-mail contains a suggestion or extra-credit assignment, not required work.

This Tuesday communication was especially important as it was the last review day before final exams. So I sent out the following pair of e-mails to my Computer Integrated Manufacturing (CIM) class:

E-mail #1

Hi CIM students!

Due to the bad weather, I won’t get a chance to see you all today, so I’m writing down a few reminders.

1) I’m beginning to go through and grade your online portfolios now.

2) Your Handshaking Project Reports (which were to be due today at 2pm) need to be turned in by noon on Friday. I will grade leniently and have given you this extension because of the snow day today, but since each group has at least three members, you absolutely should be able to complete the reports you’ve already begun and submit them before the quarter ends.

3) Our final exam is Thursday 9:10 – 10:40am. Make certain you arrive on time, and don’t forget to bring pencil, eraser, and a 1-page (8.5″x11″) single-sided sheet of handwritten notes which you will be allowed to use during the exam.

Hope you’re all enjoying the icy weather, and see you Thursday!

Best,
Mr. Yates

E-mail # 2

Also, for the iced/snowed-in, here are two CIM-related videos you might enjoy:

1) A clip on the TV show Bones where they use rapid prototyping (stereolithography) to add layers that build up a full skeleton is at http://www.hulu.com/watch/187164/bones-the-bones-that-werent#x-0,vepisode,1,0 from the 10:40-12:15 time slot (Note: video link will expire in two days). A critique of that clip, with photos of a real 3D printer recreating King Tut is at http://i.materialise.com/blog/entry/the-tv-show-bones-science-on-tv-the-largest-3d-printers-in-the-world .

2) A video here (http://boingboing.net/2008/12/19/bbtv-unicorn-chaser-1.html) shows Chris Yates (no relation) using a laser CNC machine to cut out robots (final product here http://www.chrisyates.net/reprographics/index.php?page=711).

Best,
Mr. Yates

Do you do anything work-related on snow days, or just relax in the day off?

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## Math Teacher Survey

I just filled out this survey, created by Sean Sweeney and Kate Nowak to aggregate data and information about the online math teacher community, with the goal of  creating an entrance portal welcoming new math teachers to that community and showcasing all the resources it has (we have?) to offer.

You should go fill the survey out too! [direct link to survey]

In answering the survey questions, I noticed that the blog posts I tend to value the highest are ones with great activity ideas that I can use. I chose as “killer posts” Sam’s write-up of his pendulum lab and Kate’s discussion (with videos) on her use of the spaghetti sines activity. While I greatly appreciate Dan’s “What Can You Do With This?” series, I actually picked one of his posts on an opposite-of-exemplary lesson, due to its role in clarifying thinking on how to improve our instruction.

So, in that spirit of providing activities that are useful, the two posts of my own that I chose as “killer”, or at least pretty interesting, are: Shadows, Mirrors, Scale Models, and School Measurement and Puzzling Out Some Quadratics. Let me know if you agree or have other posts that are your favorites!

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## Pi Day 2010!

A very happy pi day to all!  As many of you well know: today, March 14th (3/14), is that most famous mathematical holiday, Pi Day, to celebrate the circular constant pi = p = 3.14…

Since this special day falls on a weekend this year, I shall celebrate Pi Day with my students on Monday, the ides of March.  Of course there  will be pi(es), along with a pi internet scavenger hunt.  And I might have some student takers of the pi day digit memorization challenge on Monday too!

Rather than ramble on here1, however, I thought I’d provide you with a compendium of links to assorted pi and pi day fun resources!

• “Five tasty facts about the famous ratio” from New Scientist.  Includes pi’s connection to randomness, piems, and the intriguing discovery that the sinuosity of rivers averages about 3.14!
• One particular piem, by Michael Keith, has long been a favorite of mine.  My Baltimorean friends, fans of the Ravens, may enjoy; likewise, my fellow engineering teachers who teach a course called POE, may like this pi-restricted translation of a poem by that other Poe (Edgar Allen): Poe, E: Near a Raven.
• A pi day and daylight savings time haiku by Crystal McKenzie.
• A LiveBinders collection of pi day web resources.
• A pi-day, live, Twitter-powered mathemagic trick.
• Although I have known for years that Pi Day coincides with Al Einstein’s birthday, this year I found out for the first time that Waclaw Sierpinski, inventor of the famous Sierpinski Triangle, was born on pi day, 1882!
• A video clip of two of my former math professors, Colin Adams and Tom Garrity, debating the merits of pi (vs. e).

With that, I wish you and yours the merriest of pi days!

1: If you wish to hear my past ramblings on pi and other numbers, visit my very own pi page.

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